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aculeus

noun acu·le·us \ ə-ˈkyü-lē-əs \
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Definition of aculeus

plural aculei \ə-ˈkyü-lē-ˌī\
zoology
: a sharp-pointed process; specifically : an insect's ovipositor especially when modified into a sting

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Origin and Etymology of aculeus

borrowed from New Latin, going back to Latin, “stinger, spine (of a fish), sharp point, barb,” from acū-, stem of acus “needle” + -leus, noun suffix (perhaps originally diminutive)

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